Expansion brake, including balanced actuating mechanism



C. S. ASH

June 20, 1950 EXPANSION BRAKE INCLUDING BALANCED ACTUATING MECHNISM 4 Sheets-Sheet 1 INVENTOR.

Filed Oct. 20, 1944 Y Mw,

C. S. ASH

June 20, 1950 EXPANSION BRAKE INCLUDING BALANCED ACTUATING MECHANISM 4 Sheets-Sheet 2 Filed Oct. 20, 1944 June 2o, 195o' c. s. ASH 2,512,049

EXPANSION BRAKE INCLUDING BALANCED ACTUATING MECHANISM Filed Oct. 20, 1944 4 Sheets-Sheet 5 June 20, 1950 c. s. AsH

2,512,049l EXPANSION BRAKE'INCLUDING BALNCED ACTUATING MECHANISII Filed Oct. 20, 1944 4 sheets-snaai 4 Patented June 20, 1950 UNITED lSTATES PATENT OFFICE t .EXPANSION BRAKE, INCLUDING BALANQED Ac'rUA'riNG MEcnANisM Charles S. Ash, Milford, Mich. l Application October 20, 1944, Serial No. 559,504

(Cl. 18S-.78)

2 Claims. l

The present invention relates to vehicle Wheel assemblies, and more particularly to braking means for such assemblies.

Objects and advantages of the invention will be set forth in part hereinafter and in part will be obvious herefrom, or may be learned by practice with the invention, the same being realized and attained by means of the instrumentalities and combinations pointed in the appended claims. v

The invention consists in the novel parts, constructions, arrangements, combinations and improvements herein shown and described.

The accompanying drawings, referred to herein and constituting a part hereof, illustrate one embodiment of the invention, and together with the description, serve to explain the principles of the invention.

It is an object of the present invention to provide improved braking means for vehicle wheel assemblies. Another object of the invention is the provision of braking means for vehicle wheels that are smooth and efficient in operation and capable of long wear without replacement or repairs. 'Ihe invention further provides braking means which are relatively simple in construction and operation and thus efficient and economical to make and use. Still another object of the invention is the provision of improved braking means for dual wheel assemblies in which the individual wheels are mounted for independent relative rotation. A further objectis the provision of improved brake shoe construetion for vehicle brakes and improved brake shoe anchoring means.

Of the drawings:

Fig. l is a view of a dual, dirigible, independently rotatable wheel `assembly embodying brak'- ing means of the present invention, the view being partly in vertical cross section and partly a. side elevation:

Fig. 2 is an elevation view of the wheel 'and brake assembly shown `in Fig. 1, viewed from the inside of the assembly:

Fig. 3 is a 'View of the wheel braking means shown in Fig. 1 partly'in `horizontal cross section and partly a plan view:

Fig. 4 a detail view of the brake shoe'anchoring means taken along line '1 4 of Fie. 2':

Fig. 5 is a. side elevation of a modiiied form of brake shoe ,for the present invention; and

Fig. 6 is a detail4 Gross sectional View alone line BHG of ,liieni.y

Referring new in detail to the illustrative ernhodimentvof the invention shown by way of es? taken ample in the accompanying drawings, braking means in accordance with the invention are shown for a dirigible dual wheel assembly in which the individual wheels kare independently rotatable. As shown in Fig. 1, vthe Wheel assembly is mounted at the end of a vehicle axle I D upon the upwardly extending arm I'I secured t0 the end of the axle. The arm II is formed at its outer end "to hold a king pin whereby the wheel spindle I2 is diriglbly mounted thereon by means of an integral box-like casting I3 which is internally formed as a yoke about the end of arm II.

A pair of roller bearings I4 and I5 are provided on spindle I2 freely rotatably mounting a cylindrical hub 20, the hub having internal shoulders 2I and 22 against which bearings I4 and I5 are respectively seated. Washers I6 and I'I and nut I8 threaded on the end rof the spindle maintain the hub and bearing assembly in place. A substantially cylindrical yhub extension 23 is removably secured to the outer end of hub 20 by means of a plurality of tap bolts 24 and lock nuts 25. The outer whee1 26 of the assembly is demountably mounted on the outer end of hub extension 23 by means of mounting bolts 21, rand several cooperating nuts 28. The inner wheel 30 of the assembly is mounted for free independent rotation relatively to the outer Wheel 26 by means of a cylindrical hub 3| which is journalled on the outer cylindrical surface of hub 20. The outer hub 3| is provided at its inner end with an integral outwardly extending ange portion 32 on which wheel 30 is demountably mounted by means of mounting bolts 33 and nuts 34.

The embodied braking means for the dual wheel assembly' comprise a pair of side by side brake drums `4I) and 4I vfor correlative rotation with the respective wheels 26 and 30. The outer brake drum 4I has an integ-ral annular frustoconically formed portion 42 which is secured adiacent its inner periphery by means of bolts 44 to an outwardly radially extending flange 43 formed integrally at the inner end of hub 20. The inner brake drum k4l) is secured by means of a peripheral flange 45 to a flared integral extension 46 of flange 32l of the cylindrical hub 3|, the ilared extension enclosing'the outerl brakedrum 4I and its connecting portion 42. I

The 5 brake drums 4I) and -4'I for the dual fwheels` are provided vrwith common frictional means' for exerting a balanced brakingI effort upon the Wheels. As iilustratively embodied these means comprise asingle brake 4band 5t having on its outer surface the conventional a position intermediate `its ends.

the shoe, reaching a, maximum width at the bot--` tom. The rib 52 is so proportioned that brake shoe 50 will remain in substantially cylindrical shape whether in expanded drum engaging position or in retracted non-braking position, thus providing for smooth braking action and even wear of the friction material Brake shoe 50 is preferably a high :compression iron casting of normal shape to be out of engagement with the brake drums, returning automatically to such 'shape after expansionwithout the use otretraction springs.

The embodied expanding mechanism for brake shoe 50, as shown in Fig. 2, comprises a shaft 9 journalled in an L-shaped mount 59 which is bolted to the top of the box-like casting I3. Shaft 60 may be turned by any suitable brake actuating means (not shown) under the control of the vehicle operator to turn a brake cam 5| on the end thereof; Cam 6| is provided with a pair of concave seats 62 to accommodate spherical ends of cam' pins 53 and (i4 which are operatively connected to the ends of brake shoe 50. As shown,v the connection in the case of pin 63 comprises a concave seat 65 in an integral enlarged end portion E6 of brake shoe 53 to accommodate the otherv spherical end of pin 93, The enlarged end portion 66 `of brake shoe v5|] also serves to secure the shoe to the box-likeA The other pin 64, has its second spherical end seated in a concave seat H provided in the central portion of a .link 'l2 which is secured to an end of shoe 59 by pin 'I3 and to the baseof L-shaped support 59 4by means of pin i4. The ends of shoe 50 are thus rmly anchored through pivotal linkage to the stationary supporting member I3 of the wheel assembly, and the shoe may be expanded into frictional contact with brake drums 49 and 4| by rotary motion of cam 6|. A

Brake shoe 50 is also anchored by swinging link attachment to the stationary member I3 at As embodied, this linkage comprises asupporting member 80 bolted to the under sideA of casting I3, member having laterally extending arms 8| enclosing a pair of links 82 which are pivotally connected toa boss 83 on the inner .peripheryofshoe 50,

-by means of'a pin BIL Links 82 are also pivotallyconnected by means ofv pin 85 to the, anchored arms 8|. y

by the arrow in Fig. 2, the direction of rotation of the drums 40 and 4| in forward rotation of the vehicle is such as to result in a servo brake action by the greater of the frictional areas. It will be noted that the proportions and arrangement of the end links -61 and l2 of the brake shoe are such as to provide a uniform' expansion of the shoe with its uncentered intermediate linkage 32, thev link 'I2 for the; Igreater braking surface being substantially longer than link 6l for the lesser braking surface.

The brake shoe anchoring and expanding means for shoe 50 which have been described result in uniform expansion of the shoe and uniform pressure around its circumference, eliminating noise and grabbing in the brakes and enlcouraging smooth, eiicient operation and long wear in the friction lining 5I and other parts of the brake.

In Fig. 5 there is illustratively shown a modined embodiment of the present invention in Iwhich there are provided three substantially rigid brake shoes 99, 9| and 92 supplied -with frictional vsurfaces 93 for engagement with-brake drums 4'0 and 4| of the dual wheel assemby. Each brake shoe 90, 8| and 92 is provided with integral reinforcing framework 94 to insure rigidity and strength. The shoes and 9i are pivotally connected at their adjacent ends by means of a pin 95 which passes through a boss 96 on the end of shoe 9| and enclosing arms 9'! extending from the end of shoe 99.

Shoes 9| and 92 have a pivotal connection with each other and a swinging anchorage with the stationary casting 98 which corresponds in function and construction to the casting I3 in Figrl.

`As shown, the shoe 92 has extension arms |90 enclosing a boss IBI on the end of shoe 9| and a pin |02 extends through the membersproviding a pvoted. connection. A link |03 yis also pivotally mounted on pin |02, and likewise at its other end between extending arms |04 of casting 9B by means of pin |05. i

Expansion of the brake bands into engagement with the brake drums `is effected by means similar to those described in connection with the embodiment of the invention shown in Fig. l. A cam |01 on operating shaft |08 actuates cam pins |09 and ||0. Cam pin |09 engages the end of brake shoe 92,' the end being pivotally connected to stationary casting 98 by means of link vCam pin rIII) engages the central portion of a link ||2 which is pivotally secured both to casting 98 and the end of brake shoe 90. A coiled spring ||3 between links III and ||2 serves to keep the brake shoes in retracted position except whenpurpo'sely moved into expanded braking position by means'of shaft |08.

It will be noted Vthat the operation of the ernbodiment of the invention just described is entirely similar to that of the embodiment shown fin Fig; A1. In 4the embodiment of Fig. 5 the'shoes 90, 9| vand 92 are of substantially equal arcuate length and thus equal braking surface. The placement. of link ||l3 as a swinging anchor between shoes 9| and 92 produces a servo effect by shoes 99 and 9| when the'brakedrums rotate 'inthe direction of the arrow in Fig. 5 in forward rotation'. Links IIIVand ||2 are ofunequal-length and so mounted and actuated as-to bring the shoes 90, v9| and 92 by proportional motion into simultaneous contact with the brake drums, and

tion which have been shown and described the only brake adjustment necessary is in the shafts 60. and I 08 to properly position the shoes in nonbraking position.

VThe invention in its broader aspects is not limited to the specific mechanisms shown and described but departures may be made therefrom Within the scope of the accompanying claims without departing from the principles of the invention and Without sacrificing its chief advantages;

What I claim is:

1. A brake comprising, in combination, a drum to rotate with a member to be braked, brake shoe means within said drum to be expanded into frictional engagement therewith said shoe means extending less than the entire circumferential extent of said drums leaving adjacent ends of :said brake shoe means substantially spaced, staa point intermediate said ends of said shoe means but not centrally of the total length of said shoe means, and means for applying expanding force to said brake shoe Vmeans to move said ends distances proportional to the distances of said ends from said intermediate point, said means for applying expanding force including a link interconnecting one of said ends and said supporting means and means for applying an expanding force directly to the other of the ends of said brake shoemeans and to said link interf mediate the ends thereof.

2. A brake comprising, in combination, a drum to rotate with a member to be braked, brake shoe means within said drum to be expanded into frictional engagement therewith said shoe means extending less than the entire circumferential extent of said drums leaving adjacent ends of said brake shoe means, substantially spaced, stationary supporting means, means interconnecting said shoe means and said supporting means at a point intermediate said ends of said shoe means but not centrally of the total length of said shoe means, said interconnecting means comprising a link the ends of which are pivotally connected respectively to said supporting means and said shoe means, and means for applying expanding force to said brake shoe means to move said ends distances proportional to the distances of said ends from said intermediate point, said means for applying expanding force including a second link interconnecting one of said ends and said supporting means and means for applying an expanding force directly to the other of the ends of said brake shoe means and to said second link intermediate the ends thereof,

CHARLES S. ASH.

REFEREN CES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,658,288 Hardison Feb. 7, 1928 1,727,797 Taub et al Sept. 10, 1929 1,737,025 Sanford Nov. 26, 1929 1,739,783 Christensen Dec. 17, 1929 2,196,520 Butler Apr. 9, 1940 2,334,692 Ash Nov. 23, 1943 FOREIGN PATENTS Number Country Date 324,439 Great Britain Jan. 30, 1930 

